1. Field of the Invention
The present invention relates generally to an electro-magnetic relay, and more specifically to a relay having two flat armatures each disposed at one end of a coil and each seated at a yoke end.
2. Description of the Prior Art
A relay is disclosed in French Pat. No. 2,204,870 having first and second armatures wherein the resulting double working air gap is used to independently actuate separate switch-over contacts with each armature.
A middle contact piece is secured on the rigid armature, whereas the cooperating contact elements are anchored in a pedestal. The two armatures and their respective contact pieces are insulated from one another by an insulating intermediate ply so that two circuits are formed independently of one another.
A coincidence of the armature stroke occurs due to the direct connection of the contact piece and the armature, which can lead to intensified chatter and to misadjustment. There is also a risk, particularly due to contact burning, that the contact will not adequately close and will tend to fuse. These disadvantages are partially eliminated in that two core parts having an intervening spring are biased against the two armatures in one embodiment thereof. However, in such case, an additional insulating foil must be provided which likewise electrically insulates the armatures which have disconnected, insulating them from the core parts and from one another, whereby, in any case, the magnetic circuit is deteriorated.
In addition, there is a general problem of fusing of contacts in relays. This problem occurs with particular frequency when relatively high powers are to be output with relatively low voltages such as from a battery so that high currents flow through the contacts, for example, as in the case of motor vehicles. It is precisely in this area of employment that there is a high safety risk when a relay contact fuses in a safety device and can no longer be opened, such as, for example, in an anti-blocking system so that a high current which actually was intended to flow for only a short period of time flows continuously. This causes impermissible heating of the winding and other parts and, over and above that, can cause further damage.